Toxicity Risks of Nanomaterials Used in the Building Construction Materials

Abstract

Introduction: In recent years, there has been a growing research interest on the applications of a range of nanostructured materials in construction industry (i.e., asphalt concrete, bricks, concrete, timber, steel, and mortar), manufacturing, electronics, cosmetics, and medicine. The use of nanoscale structures in the construction industry offers exceptional physicochemical characteristics for the modification of construction materials. Nanomaterials, which are being used in cement and concretes, are carbon nanomaterials (Graphene, CNTs, CNFs), nanosilica, nano Al2O3, nanometakaoline, nano CaCO3, nano Fe2O3 and nanoTiO2. Methods: These materials improve the properties of concretes by modifying the microstructure and also improve the mechanical properties. The improvement in mechanical and durability properties of concretes in the presence of nanoparticles is due to their smaller size (<100 nm), high surface area, and energy. Results: Nevertheless, all these nanoscale particles find their way (either directly or indirectly) to various environmental matrices, such as groundwater, surface water, rivers, seas, lakes, and soil. The potential bioaccumulation of metal oxide nanostructures results in undesirable effects on animals, aquatic biota, plants, and humans. Therefore, it has become crucial to determine toxicity levels during the use of these multifunctional nanoscale materials. Conclusion: This study presents an overview of the advantages and disadvantages of nanomaterials in concretes and related materials. A particular emphasis has been given to discuss the potential toxicity risks of nanomaterials used in building construction materials.